Kirigami‐Tailored Auxetic Ceramic Meta‐Aerogels for Tensile‐Invariant Thermal Protection

ABSTRACT Ceramic aerogels exhibit exceptional thermal insulation potential in extreme environments, yet their poor stretchability and transverse contraction prevent them from providing conformal thermal protection. These limitations render ceramic aerogels inadequate for aircraft evolving toward hypersonic speeds and morphing configurations. This study employs a topology‐guided multiscale structural strategy, fabricating auxetic ceramic nanofiber aerogels, based on theoretical mechanical models of Timoshenko beam theory and Castigliano's theorem. Leveraging a kirigami‐inspired design that integrates reentrant honeycomb structural membranes to resist transverse contraction and isotropic aerogels to block heat leakage, our auxetic aerogels enable outstanding stretchability and tensile‐invariant thermal insulation properties. Specifically, our aerogels achieve an excellent tensile elongation of up to 22% strain with a fracture stress of 31 kPa fracture stress and a Poisson's ratio of −0.49. Moreover, these aerogels also demonstrate excellent fatigue resistance, enduring 500 stretch‐recovery cycles at a 10% strain without any damage. Furthermore, the aerogels possess ultralow thermal conductivity (33.14 mW·m −1 ·K −1 at 20% strain) while maintaining exceptional thermal stability at 1100°C, resisting tensile deformation without transverse contraction. This study shows promising prospects for lightweight, reliable thermal protection in extreme environments.